Pot-type oil burner and igniter



y 1953 H. c. LONG I POT-TYPE OIL BURNER AND IGNITER 2 Sheet s-Sheet 1 Filed Oct. 17, 1947 IIIIIIIIIIIIIIIIIIII III 6 |.l I 6 I @3 I.

Fll I p. I 4 I 0 HARRY C LONG ATTORNEY m m IA July 21, 1953 H. C. LONG POT-TYPE OIL BURNER AND IGNITER Filed Oct. 17, 1947 2 Sheets-Sheet 2 i f 42 53 l H.

I1 1 'pa l 43 I 1 2- 7" s3 7 .52

mmvm; LONG ATTORNEY HARRY c Patented July 21, V 1953 POT-TYPE OIL BURNER AND IGNITER Harry 0. Long, Portland, 0reg., assignor to Reliance Manufacturing Company, Incorporated, Portland, 0reg., a corporation of Oregon Application October 17, 1947, Serial No. 780,413

3 Claims.

My present invention is an improvement upon the invention illustrated, described and claimed in my co-pending application, now Patent No. 2,520,159, entitled Igniter for vaporizing Oil Burners of the Open Receptacle Type, issued August 29, 1950.

The primary purpose of the present invention is to provide a vaporizing oil burner with an intermittent electric igniter, the vital elements of the igniter being removed from or protected from theheat and corrosive conditions occurring within the combustion area. In the above identified patent I have disclosed an igniter element particularly adapted for fabrication into a burner of the type disclosed and claimed in the patent to Daniels, No. 2,083,832 of June 15, 1937, the application thereof to the burner requiring modification of the burner and some fabricating steps. An object of the present invention is to make the igniter applicable to any form of vaporizing burner without essential modification thereof.

The principal object of the present invention is to provide an igniter which may be subjected to combustion conditions during periods when the burner is being ignited, but which will be free of combustion conditions when the burner is in operation. In the combustion region of an oil burner, particularly in the hydroxilating type of burner, the high temperature and corrosive gases occurring at certain points in the transi tion of the fuel from liquid to vapor to products of combustion reduce the life of exposed parts. Also, in the combustion region a certain amount of carbon is deposited, which after a period of time may accumulate to such an extent that it becomes necessary to clean out the soot deposits. This cleaning operation requires a certain amount of poking and scraping with elongated and sometimes sharp instruments which, particularly in the hands of the average burner user unfamiliar with the fine details of the burner, might irreparably damage exposed fragile parts. Thus a further object of the present invention is to increase the lifeexpectancy of an igniter by making it so constructed as to be installed outside of the combustion zone and inaccessible to probing or scraping instruments, and also to be exposed to combustion conditions only during initial lighting of the burner and therefore not likely to be covered by soot deposits. Y

It is well known in this field of combustion that a fine balance must be achieved between the fuel supply and air supply, which balance, due to the varying conditions of draft and other factors, can usually only be achieved by trial and fects the combustion characteristics of the burner to the least possible degree, and the operation ofwhich may in itself be adjusted.

The objects and advantages of the present invention may be more readily understood from inspection of the accompanying drawing wherein preferred embodiments of the invention are illustrated, taken in connection with the following specification wherein lik numerals refer to like parts throughout, while the features of novelty will be more particularly pointed out in the appended claims.

In the claims Fig. l is a vertical section through a burner of the type disclosed in the patent to Daniels, No. 2,083,832 and having the present invention associated therewith;

Fig. 2 is a front view partially in vertical section taken substantially along line 2-2 of Fig. 1;

Fig. 3 is a verticalsection on an enlarged scale taken substantially along line 3-3 of Fig. 2;

Fig. 4 is a horizontal section on an enlargedscale taken substantially along line li of Fig. 2;

Fig. 5 is a section similar to Fig. 3 of a modified form of the invention with the igniter resistance element removed;

Fig. 6 is a vertical section through a warm air furnace utilizing a modified form of burner having the present invention applied thereto;

Fig. 7 is a vertical section taken substantially along line 'l'i of Fig. 6; and

Fig. 8 is a horizontal section taken substantially along line 8-4 of Fig. 7.

Referring to Figs. 1 to 4 inclusive the present invention is illustrated in association with an air chamber it enclosing a combustion chamber H having a triangular cross section so as to provide means to retain a slight pool of oil at the inner end of the combustion chamber. Primary air may enter the combustion chamber to mix with and cause combustion of the vaporized fuel oil through openings [2 in the top wall of the combustion chamber, and secondary air may reach the flame through openings IS in the front wah of the air chamber adjacent the horizontal flame opening M. Air may enter the air chamber by gravity action, or may be forced th reinto by a blower I5. In either event the walls of the combustion chamber ll extend from side to side of the air chamber so that the air emerges only above and below theflame opening. Oil is fed to the'combustion chamber through an inlet tube It extending through the rear wall I! of the combustion chamber, the oil being admitted under control of the usual control system including a float valve or the like (not herein illustrated).

In order initially to ignite the oil I provide an igniter comprising means 20 forming a hollow, walled pocket on the outer surface of the burner. The means 21] may comprise three vertical side walls joined by an inwardly sloping bottom wall 2t, the pocket having an open upper end or mouth. An insert comprising a flanged member 22 surrounding a plug 23 composed of ceramic or other heat-proof dielectric material fills the upper open end of the pocket to provide an airtight chamber against the wall of the burner. An air inlet opening 24 is provided in the side wall of the burner on the air inlet side of the combustion chamber wall H and an ignition flame opening 25 is provided in the wall of the burner on the combustion chamber side of the rear wall H. The opening 24 is preferably adjacent the top of the pocket and the opening 25 adjacent the bottom thereof. A pair of conductors 26 are embedded in the ceramic plug 23, the conductors being fused to a bail-like resistance element 21 extending into the pocket. Supported upon the element 21 and leaning there-against by virtue of it being longer than the vertical space between the bottom wall 2! and the element 21 is a wick. member 28 of heat and corrosion resistant porous material such as ceramic, asbestos or sintered powdered metal, the latter substance being preferred. Preferably the wick member has a round end to cause it to lean against the bail resistance element 21 in firm contact therewith. Reference to the above identified co-pendin application will disclose modifications-in detail and arrangement of the wick member.

The device is installed with the lead Wires 26 connected to a source of current such as would be provided by the output side of a suitable transformer, the current being such with reference to the electrical characteristics of the resistance element to heat the element in short order to a high degree, thereby vaporizing and igniting fuel oil which may have been soaked up in the pores or capillary passages of the wick member 28. Air to support combustion enters through the opening 24 and the flame is projected outwardly through the opening 25 across the surface of the pool of oil in the lower rear corner of the combustion chamber.

It is to be remarked at this point that the lower edge of the ignition flame opening 25 is spaced above the normally maintained oil level in the combustion chamber so that only when heat is desired and the automatic controls cause flow of fuel oil and heating of the resistance element will the oil pool in the combustion chamber increase in depth to permit a slight amount to flow into the pocket formed between the wall of the burner and the sloping bottom wall 2| of the pocket-forming means. As soon as this occurs oil will be soaked up by the wick member and in very short order will be ignited by the resistance element to provide an ignition flame. The ignition flame will traverse at least a portion of the oil in the combustion chamber, raising the temperature thereof and causing vaporization of the oil and ignition of the resulting vapor. The heat of combustion from the main pool Will continue to evaporate the oil and cause continued burning as long as oil flows into the burner. During this normal burning period the level of the oil in the combustion chamber will be maintained below the bottom edge of the ignition flame opening 25 so that in a short period of time after initial combustion no further flame will exist within the pocket interior. Furthermore the circulation of air will continue through the pocket to keep corrosive gases from entering the pocket, and also to minimize the effect of radiation to the igniter parts.

In Fig. 5 I have illustrated a modification which the invention may assume in which the side walls of the means 20 support horizontal slides 30 and 3! having elongated openings therein 32 and 33, respectively, which are adapted to coincide with the ignition flame opening 25 and the air inlet opening 24, respectively. The lower edge of the slot 32 is inclined so that the height to which the oil pool must rise in order for oil to enter the igniter pocket may be varied. Also the slot 33 is tapered so that the effective diameter of the air inlet opening to the pocket may be varied. The foregoing is merely exemplary of means for adjusting the performance of the igniter assembly. Also the slides are preferably provided with imperforate sections of sufficient size to close 01f the pocket from the combustion chamber if desired.

In Figs. 6 to 8 inclusive I have illustrated the invention applied to a warm air furnace 4B including a heat exchanger 4! having a smoke stack 12 associated therewith and from the bottom of which depends a commonly encountered type of combustion chamber 43 which is substantially cup-shaped. As seen in Fig. '7 the combustion chamber 43 may have a plurality of air inlet holes 44 therein of varyin sizes, number and other characteristics, and the upper end of the chamber may be closed by an annular plate 45 having a flame opening 46 centrally thereof. The interior of the chamber may be further divided by centrally apertured bafiles such as the flat annular plate 4! and the conical collar 68. The foregoing is merely exemplary as numerous modifications in arrangement and detail of such burners are well known to all skilled in the art. I have illustrated an igniter pocket 56 attached to the outer surface of the combustion chamber, the pocket being similar in most respects to that previously described inasmuch as it comprises vertical side walls and an inwardly sloping bottom wall 5|, and its upper end is closed by a ceramic plug 52 through Which pass electrical leads 53 terminating in a resistance element 54 supporting a wick member 55.

The fuel oil is admitted to the combustion chamber through an inlet tube 60 under control of the usual controls (not disclosed). Air to support combustion enters the combustion chamber through the holes 44 from the space surrounding the combustion chamber, in some cases being supplied under pressure by a blower 5i forcing air into a plenum chamber 62 having an outlet 63 into the air heating chamber containing the heat exchanger and combustion chamber. It is preferred that a well 64 be provided in the bottom of the combustion chamber into which oil may flow from the tube 60, and the ignition flame opening 65 from the interior of .the pocket is located above the well, the lower edge thereof being at or slightly below the level of the principal portion of the inner surface of the bottom wall of the combustion chamber. The air inlet 65 to support the ignition flame in the pocket is above the wick and in the outer wall of the pocket so that air may be supplied thereto from the source of combustion supporting air. I have illustrated the leads 53 as extending to a transformer 61 conveniently mounted upon the outer surface of the furnace or the like.

In operation, a slight amount of oil will flow into the angular recess between the outer wall of the burner and the bottom wall 5i of the pocket, whereupon the heat of the resistance element 54 will cause vaporization and ignition of a the oil soaked up into the wick member 55. The flame therefrom will project outwardly from the ignition flame opening 65 initially to ignite the pool of oil in the Well 54. The vapor from said f within the pocket so that replacement of defective parts may be accomplished without removing the pocket-forming means from the burner body. Also the leads 53 may terminate in bare ends ready for attachment to transformerssupplied from someother source.

Having illustrated and described preferred embodiments which my invention may assume it should be readily apparent to those skilled in the art that the invention permits of other modifications in detail and arrangement. All such modifications as come within the true spirit and scope'of the appended claims are considered to be part of my invention.

I claim:

1. An igniter for a vaporizing oil burner of the type comprising an open burner receptacle having a wall and a bottom, said burner receptacle having air and fuel inlet openings thereinto; comprising means for forming a pocket on a portion of the outer surface of the wall of the burner receptacle spaced from said fuel inlet opening, said pocket having a mouth at its upper end and a closed lower end below the level to which oil may rise in saidburner receptacle, a plug of heat-resisting, electrical insulating material closing said mouth, a pair of conductors extending through said plug into said pocket, said conductors being insulated from each other and from the pocket-forming means by said plug,

a resistance element joining the ends of said conductors in said pocket, and a wick member 1 suspended from said resistance element and extending into proximity with tthe lower end of said pocket, said pocket having an air inlet opening thereinto and said wall having an ignition fiame opening therethrough connecting themterior of said pocket with the interior of said burner receptacle, the lower edge of said ignition flame opening being above the adjacent portion of the bottom of said burner receptacle and below the level to which oil may rise in said burner receptacle.

2. An igniter for a vaporizing oil burner of the lower end, a plug formed of ceramic closing said I mouth, a pair of conductors extending through said plug into said pocket, said conductors being insulated from each other and from the pocketforming means by said plug, a resistance element joining the ends of said conductors in said pocket, and a wick member suspended from said resistance element, said pockethaving an air inlet opening thereinto in an upper region thereof and said wall having an ignition flame opening therethrough within the area defined by said pocket, the lower edge of said ignition flame opening being closely above the adjacent portion of the bottom of said burner receptacle and above the lower end of said wick member.

3. A'liquid fuel burner comprising an open receptacle including a bottom and a wall and having air and fuel inlet openings thereinto, vaporization of the fuel being generated in said burner receptacle by the heat of combustion, and an igniter comprising means forming a pocket on a portion of the exterior surface of the burner receptacle spaced from said fuel inlet opening, said pocket having an opening at its upper end and a closed lower end, a plug formed of heat resisting, electrical insulating material closing said upper end opening, a pair of conductors extending through said plug into said pocket, said conductors being electrically insulated from each other and from said pocket-forming means by said plug, electric fuel vaporizing and igniting means in said pocket and including a portion in circuit with said conductors, there being an ignition flame opening connecting the interiors of said burner receptacle and said pocket, the lower edge of said ignition flame opening being above the bottoms of said pocket and of said receptacle and below the level to which fuel may rise in said receptacle whereby fuel may flow from said burner receptacle into the closed lower end of said pocket and an ignition flame may project from said pocket into said burner receptacle across the surface of fuel therein.

. HARRY C. LONG.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,810,035 Valjean June 16, 1931 2,056,146 Sherman W Sept. 29, 1936 2,083,832 Daniels June 15, 1937 2,239,175 Unser Apr. 22, 1941 2,274,475 Focke et a1 Feb. 24, 1942 2,307,007 Alain Jan. 5, 1943 2,353,880 Cooper July 18, 1944 2,438,823 Resek et al Mar. 30, 1948 

